/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.beam.runners.dataflow.worker.streaming.config;

import java.util.function.Consumer;
import javax.annotation.concurrent.ThreadSafe;
import org.apache.beam.sdk.annotations.Internal;

@Internal
@ThreadSafe
public interface StreamingGlobalConfigHandle {

  /** Returns the latest StreamingGlobalConfig */
  StreamingGlobalConfig getConfig();

  /**
   * Subscribe to config updates by registering a callback. Callback should be called the first time
   * with settings, if any. The callback could execute inline before the method returns.
   */
  void registerConfigObserver(Consumer<StreamingGlobalConfig> callback);
}
